Put back golang v1.21.x in ci workflow

To address the following build errors in ci workflow:

Autobuilder was built with go1.21.7, environment has go1.21.7.
Error: We were unable to automatically build your code. Please replace the call to the autobuild action with your custom build steps. Encountered a fatal error while running "/opt/hostedtoolcache/CodeQL/2.16.3/x64/codeql/go/tools/autobuild.sh". Exit code was 1 and last log line was: 2024/02/28 18:16:40 Extraction failed: exit status 1. See the logs for more details.

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
   linux-tests:
     strategy:
       matrix:
-        go: [ 1.22.x ]
+        go: [ 1.21.x ]
     runs-on: ubuntu-20.04
     timeout-minutes: 15
 
@@ -40,7 +40,7 @@ jobs:
     - name: Setup Go
       uses: actions/setup-go@v3
       with:
-        go-version: "1.22"
+        go-version: "1.21"
     - name: checkout code
       uses: actions/checkout@v3
     - name: golangci-lint